We present PalmType, which uses palms as interactive keyboards for smart wearable displays, such as Google Glass. PalmType leverages users’ innate ability to pinpoint specific areas of their palms and fingers without visual attention (i.e. proprioception), and provides visual feedback via the wearable displays. With wrist-worn sensors and wearable displays, PalmType enables typing without requiring users to hold any devices and does not require visual attention to their hands. We conducted design sessions with 6 participants to see how users map QWERTY layout to their hands based on their proprioception. To evaluate typing performance and preference, we conducted a 12-person user study using Google Glass and Vicon motion tracking system, which showed that PalmType with optimized QWERTY layout is 39% faster than current touchpad-based keyboards. In addition, PalmType is preferred by 92% of the participants. We demonstrate the feasibility of wearable PalmType by building a prototype that uses a wrist-worn array of 15 infrared sensors to detect users’ finger position and taps, and provides visual feedback via Google Glass.